As is known, electrical appliances such as deep fryers and electric frying pans are often used by individuals in the preparation and cooking of meals. These electrical appliances typically include a power cord that is receivable within a corresponding electrical outlet for supplying electrical power to the appliance. It can be appreciated that by utilizing a power cord to supply electrical power to the appliance, such cord may constitute a potential hazard to those parties in close proximity thereto. For example, each year a substantial number of children may tip over an electrical appliance by inadvertently engaging its power cord. In appliances that utilize oil or other fluids that have elevated temperatures, the accidental tipping of such electrical appliance may result in significant injury to a party in close proximity to the appliance.
In certain electrical appliances such as electric frying pans, thermostatic control devices are utilized to insure that the cooking surface of the electrical appliance is maintained at a proper temperature. Typically, these thermostatic control devices include a temperature probe which is removably attached to the electrical appliance by insertion into a female receiver. This, in turn, allows the thermostatic control device to be separated from the electrical appliance thereby allowing the electrical appliance to be immersed in water for cleaning. In order to minimize the risks associated with utilizing a power cord with such electrical appliances, the thermostatic control device is usually connected to a power source by a detachable power cord. Current Underwriters Laboratories, Inc. (UL) standards require that the force required to separate the power cord from the thermostatic control device shall be at least 5% less than the force required to overcome the static friction of the electrical appliance on a supporting surface such as a countertop or the like. Consequently, various detachable power cord devices have been developed that meet the present UL standards and that provide electrical power to appliances that utilize thermostatic control devices.
By way of example, Mendelson et al, U.S. Pat. No. 6,607,391 discloses various embodiments of a detachable power supply apparatus for use with electrical appliances. The electrical appliance includes a removable temperature control device having a mounting panel incorporating a ferrous contact plate and a pair of conductive pins extending therefrom. The power supply cord includes a female electrical receptacle for receiving the pair of conductive pins extending from the mounting panel. In addition, the female electrical receptacle may incorporate a magnet subassembly that is directed toward the ferrous contact plate of the mounting panel for maintaining the electrical connection between the conductive pins and the female electrical receptacle. It is intended that the arrangement require a predetermined tensile or pulling force and a preselected shearing or lateral force to overcome the magnetic force generated by the magnet subassembly in order to allow a user to disengage the female electrical receptacle from the mounting panel of the temperature control device.
While functional for its intended purpose, the detachable power supply apparatus disclosed in the '391 patent has certain limitations. By way of example, the magnetic force generated by the magnet subassembly of the power supply cord may vary. As a result, the preselected tensile or shearing force required to disconnect the power supply cord from the temperature control device may inadvertently fail to meet the present UL standard. Alternatively, the magnetic force provided by the magnet subassembly may be insufficient to insure proper electrical contact between the pair of conductive ends of the temperature control device and the female electrical receptacle of the power supply cord thereby rendering the detachable power supply apparatus ineffective for its intended purpose. Further, incorporating the magnet subassembly into the power supply apparatus increases to overall cost of the electric frying pan.
Therefore, it is a primary object and feature of the present invention to provide a detachable power cord apparatus that may be utilized to interconnect an electrical appliance or a temperature control device to a power source.
It is a further object and feature of the present invention to provide a detachable power cord apparatus for use with an electrical appliance or a temperature control device therefore that may be detached from the appliance or the temperature control device in response to a predetermined lateral force or a predetermined shear force thereon.
It is a further object and feature of the present invention to provide a detachable power cord apparatus for use with an electrical appliance or a temperature control unit that is inexpensive to manufacture and simple to utilize.
In accordance with the present invention, a connection device is provided for operatively connecting a temperature control housing of an electrical appliance to a power source. The connection device includes upper and lower spaced connection surfaces projecting from the control housing and defining a cavity therebetween. The upper and lower connection surfaces include corresponding catches axially aligned with each other. A power cord housing supports a first end of a power cord. The power cord housing has upper and lower surfaces and a forward end receivable between the upper and lower connection surfaces. A first detent element is movable between a first extended position wherein the first detent element projects from the power cord housing and is receivable in one of the catches and a second retracted position.
The connection device may also include a second detent element movable between a first extended position wherein the second detent element projects from the power cord housing and is receivable in the other of the catches and a second retracted position. It is contemplated for the first and second detent elements to take the form of ball bearings. In its extended position, the first detent element projects from the upper surface of the power cord housing. In its extended position, the second detent element projects from the lower surface of the power cord housing. A means is provided for biasing the first and second detent element toward their extended positions. The means for biasing the first and second detent elements may include a spring extending therebetween.
In accordance with a further aspect of the present invention, a connection device is provided for operatively connecting a temperature control housing for an electrical appliance to a power source. The connection device includes first and second connection surfaces that project from the control housing and that partially define a cavity. Each connection surface includes a corresponding depression therein. A power cord housing supports a first end of a power cord. The power cord housing has first and second surfaces and a forward end receivable within the cavity. A first detent element is movable between a first extended position wherein the first detent element projects from the power cord housing and is receivable in the depression in the first connection surface and a second retracted position. A second detent element is movable between a first extended position wherein the second detent element projects from the power cord housing and is receivable in the depression in the second connection surface and a second retracted position.
It is contemplated for the first and second surfaces to be generally parallel to each other and for the first and second detent elements to include ball bearings. In its extended position, the first detent element projects from the first surface of the power cord housing. In its extended position, the second detent element projects from the second surface of the power cord housing. Means are provided biasing the first and second detent elements toward their extended positions. Preferably, the means for biasing the first and second detent elements includes a spring extending therebetween.
In accordance with a still further aspect of the present invention, a connection device is provided for operatively connecting an electrical appliance to a power source. The connection device includes a temperature control device having leading and trailing ends. The temperature control device has first and second connection surfaces projecting from the trailing end to partially define a cavity. Each connection surface includes a corresponding depression therein. A power cord housing supports a first end of a power cord. The power cord housing has first and second surfaces and a forward end receivable in the cavity partially defined by the connection surfaces of the temperature control device. A first detent element is movable between a first extended position wherein the first detent element projects from the power cord housing and is receivable in the depression in the first connection surface and a second retracted position. A second detent element is movable between a first extended position wherein the second detent element projects from the power cord housing and is receivable in the depression in the second connection surface and a second retracted position. Biasing structure is provided for urging the first and second detent element toward their extended positions.
The temperature control device further includes a temperature sensor extending from the leading end thereof for sensing the temperature of the electrical appliance. In addition, first and second appliance terminals communicate with the leading end of the temperature control device. The trailing end of the temperature control device includes first and second power cord terminals. A thermally-responsive switch is operatively connected to the temperature sensor. The switch is movable between a closed position wherein the power cord terminals are electrically coupled to corresponding appliance terminals and an open position wherein the power cord terminals are electrically isolated from corresponding appliance terminals in response to the temperature sensed by the temperature sensor.
The power cord housing may include first and second power supply terminals communicating with the forward end thereof and interconnected to the power cord. The power supply terminals are connectable to the power cord terminals of the temperature control device. The first and second connection surfaces of the temperature control device are generally parallel to each other. The first and second detent element include ball bearings. In its extended position, the first detent element projects from the first surface of the power cord housing and is receivable in the depression in the first connection surface. In its extended position, the second detent element projects from the second surface of the power cord housing and is receivable in the depression in the second connection surface. The biasing structure includes a spring that extends between the first and second detent elements.